1. Field of the Invention
The present invention relates to a turbine blade fatigue life evaluating method.
2. Description of Related Art
A gas turbine comprises a compressor, a combustor, and a turbine (not shown in the drawings). According to such a gas turbine, compressed air which is compressed in the compressor is supplied to the combustor, and the compressed air is mixed with a fuel which is supplied separately, and combusted. A combustion gas which is generated in the combustor is supplied to the turbine so as to generate a rotational driving force at the turbine.
In FIG. 6, an example of an internal structure of such a turbine is shown. As shown in FIG. 6, in the turbine, a plurality of turbine blades 1 which are disposed circularly on a rotor which is not shown in the drawing, and a plurality of turbine stationary blades 2 which are disposed on a stator around the rotor are disposed alternately in the rotational axis direction (horizontal direction in FIG. 6) of a rotor. Also, a combustion gas flow channel 3 through which the combustion gas passes is formed. The combustion gas which is introduced into the combustion gas flow channel 3 from the combustor rotates the turbine blades 1 and applies a rotational force to the rotor. Such a rotational force rotates a power generator (not shown in the drawing) which is connected to the rotor so as to generate electric power.
However, in such a gas turbine, a method for quantitively evaluating and managing the fatigue life of the turbine blade 1 has not been established; therefore, there is a concern that the entire of the gas turbine may be damaged if a creep defect occurs unexpectedly.